VP:DS- Done with the C ending path.
It's pretty much just a gaiden of the VP series, taking a look at the world a bit before the VP1 events. It's really cool for that, the game takes full advantage of VP1/2's style. The story has it's moments, but by and large Wyl isn't connected to it. Half the time there is no reason for him to be in the scenes, and as a character he bounces from a random sociopath to the do gooder of the day.
The A Ending actually fills in Wyl's role a little more. WARNING, VPDS SPOILERS
POSSIBLY!
If Wyl doesn't get around to actually killing anyone else with the Plume, then Ailyth and friends get mad, explaining that they put a lot of work into sewing the seeds of the whole war and leading Wyl to as many battles as possible to create the Angel Slayer. So, really, Wyl is the central feature of the whole war, and the forces of EBIL are pulling the strings for him. A Ending Wyl (the not-sociopath one) is understandably upset by this.
Since it came up in chat, I wanted to discuss VPDS and Wyl's seemingly misguided grudge against the Valkyrie. Now, obviously if you've played VP1 or 2, Wyl's hatred of the Valkyrie is pretty foolish, she had nothing to do with the death of his father (though arguably she is indirectly responsible for the death of his sister and his mother's insanity since she left behind the plume, but more on that later).
But in the time period/perspective of VPDS, we're not getting a Deity's point of view of the world. We're seeing Midgard from the common people a little more closely, with all the intrigue of the gods mostly hidden from view. Sure, everyone believes in the Gods and Asgard and Vahalla and all of that, but they very rarely come in contact with actual supernatural phenomenon. Even Mermaids and Dragons were somewhat rare in VP1.
Compare to modern-day religious people. There are many who strongly believe in the existence of God in some form or another, but there's a lot of disagreement on how exactly God works and behaves. The deities of VP are a lot easier to pin down as personalities, granted, but the common folk are still primarily going off of hearsay. Their parents told them the stories of the gods (probably slightly different stories depending on your family, too), and the only physical proof 95% of the population really has of their existence is the plume left on the corpse of the supposed Einherjar. Not everybody is Rufus, the half-elf chosen to be Odin's body double, or Lezard the mad genius top student of the magic academy, so the proof of deities is pretty lacking. But in VP1, we always got the impression that the common folk who were chosen to be Einherjar were pretty wise about how the Valkyrie worked. They knew the stories.
When I was playing VPDS, I remembered having a similar initial reaction - why the hell is Wyl pissed at Lenneth? So I kept searching for clues confirming that Wyl was an idiot. I kept waiting for someone to say "The Valkyrie doesn't kill people". Instead, I kept seeing the phrase "It is a great honor to be chosen to be with the Valkyrie". You know what this reminds me of? It sounds a lot like the things people say to comfort the families of soldiers who have 'died valiantly' in a war effort. And I'm sure it comforts the families of supposed Einherjar about as much as it does the real-world soldiers' families. Only the VP families are given a single deific figure to blame. Sure, some people probably see it as 'The Valkyrie takes those who have already fallen in battle'; but there are obviously some (Wyl's mother, Valmur's family) who have come to the conclusion that 'The Valkyrie -causes- those she chooses to fall in battle'. She is a -god- after all, it wouldn't be that big of a logical leap to make.
And, looking more specifically at Wyl, he is a child of his mother. Wyl was pretty young when his father died in battle, and from the moment the Plume was given to him, his mother began to rail against the gods, the Valkyrie, for taking him away. Raised in this kind of environment, with the only opposing sentiment being 'but your father's death was -honorable-', it's hardly surprising that Wyl developed the single-minded hatred for the Valkyrie that he displays in-game.
And in specifically C path, his sociopathic tendencies have been -cultivated- by Ailyth and Hel's influence. Wyl goes his entire life burdened by his broken family, with his insane mother's views drilled into his head, and his father's and sister's deaths causing a constantly-simmering anger to build up, and then one day, he dies in battle. But, his life is spared by (he thinks) a goddess telling him that he can finally get revenge on the Valkyrie - what he's ALWAYS wanted. He just has to hold up a feather. That's all. Sure, it'll kill someone, but that's all Wyl has to do, and she -did- just bring him back to life after all. First rule of persuasion, ask for a little bit at a time and people will eventually agree to anything. So Wyl and Ancel are in a tight spot later on, "hold up the feather! it's your only chance!" urges Hel. So he does, and hey, Ancel's stronger than ever! Maybe he'll be okay?
Well, Ancel dies. And even though Wyl didn't want to do it, he knows he's killed him. He's in shock, and grief, and he runs away from his comrades and anyone who would have (possibly) helped him. Well, they may have also killed him, but either way, he runs right into Ailyth, Hel's mouthpiece. Forget his father and sister, he's just killed his best friend, and he's not even able to begin grieving or dealing with his guilt when she tells him "it's okay little boy, it's not your fault. It -had- to happen. Think about your father, your sister, your anger." So she jumps him right into stage 2: Anger, and she keeps him there as long as it takes to get him to kill more people with the Plume. And now Wyl's stuck - he's already gone this far in, he KILLED Ancel (nevermind the circumstances behind that anymore), there's war all around him, and the Valkyrie is still out there, killing people and ruining families (as Wyl sees it anyway). What's a little more bloodshed when he can finally kill her?
The game doesn't explore all of this thoroughly with Wyl, but this is certainly where the story seemed to be pointing when I played the game. The individual intrigues along the way (except for perhaps Valmur/Phiona/Reinhilde/Auguste's story, which is where I gleaned most of Wyl's development in parallel, personally) are largely world-building. Though they do drop some subtle hints as to Ailyth's involvment in starting the war, which itself is just a side-story to Hel's plot to get Wyl to kill Lenneth.
A Ending, of course, would be the opposite for Wyl. Instead of getting mired in Ailyth's suggestions, he's strong-willed enough to look past Ancel's death and not inflict the Plume on anyone else. Personally, I find that kind of boring, as RPG heroes always seem to find this kind of strength, and I like Wyl as a misguided villain-type.
Back to C-path, Reinhilde and Auguste (and in some ways, their children) are interesting foils to Wyl. They are also suffering the loss of a son, who has the infamous Valkyrie plume left behind on his corpse. Phiona adamantly asserts that this is an honor, while her parents just wish he was still alive. They would have -none- of their children go to war if they could help it, despite House Haughn being a military house. Eventually, this argument over the son's Einherjar-hood leads to the death of both children (or in B path, both parents), and the remaining family members decide to follow Wyl, who understands what it's like to lose family members both 'directly' and indirectly due to the Valkyrie's actions. After all, if Wyl's mother hadn't lost it due to blaming the Valkyrie all the time, Wyl's sister might still be alive. Just more impetus for Wyl to want to kill Lenneth.
The argument that came up in chat was that Wyl was emo and his motivation was stupid. While I agree that he's definitely emo (and melodramatic), his motivation is pretty solid, even if the game rarely touches on it directly. I honestly felt that if the game went out of its way to beat all of the above explanation into the player's face at every turn, it would have been worse than the 'lack of exploration' we got instead.